1. Field of the Invention
The present invention relates to a structural component attached between vertical structures in a building to reinforce the vertical structures therewith and, more particularly to a component to strengthen mullions as the vertical structure when the mullions supporting a curtain wall are arranged in a building at relatively long intervals to each other in order to provide an opening for a door way in a building wall formed by the curtain wall.
2. Description of the Related Art
It has been known in the art that the curtain wall is a preferable material to form an outer wall of the building. The curtain wall is generally assembled such that a panel or "curtain wall unit", such as glass panel, aluminum panel or stone panel is hung on the mullions standing upward between the upper and lower floors.
Regarding the mullion, it has been known as being made from a square-shaped aluminum pipe or a steel H-beam or square pipe, but the present applicant proposed in Japanese Utility Model Application No. Hei 3-52672 (Japanese Utility Model Laid-open No. 4-137115), a mullion having the trussed structure consisting of two exterior and interior vertical members of cylindrical pipe and plural lattice trusses extending between and connecting to both vertical members. As has been taught, the mullion of the applicant assured high strength even if it did not have large sectional area, which was preferable to make a space for installation small compared with that in the conventional H-beam, and to be open.
The interval of two mullions side-by-side will be naturally determined based upon a dimension of the glass panel or a length of transom supporting the top and bottom of the glass. It is therefore required to consider the intervals of two mullions taking into account the strength of the glass panel.
Accordingly, the distance between two mullions could not be made large, so that it was impossible to have a large opening for a door way or a wind shield room at the building wall formed by the curtain wall.
Otherwise, if it is required to have a large opening at the curtain wall, one or more auxiliary beams will be additionally applied between the mullions for which intervals are relatively large in order to overcome the loss in strength, and to provide auxiliary mullions to support panels arranged over the opening. The auxiliary beam is generally a H-beam having a large area to obtain enough strength, so that a space occupied by the auxiliary beam tends to be large unexpectedly, spoiling the opening of the curtain wall covered with glass panels, and ruining the design as a whole.
The auxiliary beam of H-beam applied between the mullions to support the curtain wall further involves other disadvantages regarding space and to be open because its area should be considered so as to support two loads, one acting in a vertical direction by the weight of the curtain wall and the other acting in a horizontal direction by the wind.
In general, there is a scale gap between the vertical load and the horizontal load, but the auxiliary H-beam does not naturally correspond to such difference because of its shape, so that the H-beam should be chosen to bear a bigger load. Hence the selected beam is useless in view of weight control in a building.
The already mentioned mullion disclosed in the Japanese Utility Model Application No. Hei 3-52672 (Japanese Utility Model Laid-open No. 4-137115) is suitable to be intentionally disposed inside upon design, but in view of a safe structural design, such an auxiliary H-beam having a different structure compared with the trussed structure of the mullion does not ensure an effective load dispersion, transmission or design integration.
Accordingly, an object of the present invention is to effectively support both loads in the vertical and horizontal directions, does not require a relatively large area to obtain enough strength, much particular space for installation to improve to be open and plenty of members to reduce cost and to provide a structural component having enough strength.
Another object of the present invention is to provide a structural component capable of assembling easily without assembling error.
Still another object of the present invention is to provide a structural component keeping a substantial unification with the mullions in a structural and design view, which does not spoil the design even when it will be used inside of the building.